Synchronizing apparatus.



L. JANSS ENS. SYNCHRONIZING APPARATUS. APPLICATION FILED APR. 10, 1913..

Patented Dec. 26,1916.

2 sums-saber:

L. MNSSENS.

sYucunomzme APPARATUS. Armcmon mm Armlo. ma.

Pmmd Dec. 26,1916.

ZSHEETS-SHEETZ.

UNITED srrnrrs OFFICE.-

'-, LOUIS JANSSENS, OFF-BRUSSELS, BELGIUM.

SYNCHRONIZING APPARATUS.

. Application filed April 1 0, 1913. Serial No. 760,281.

T0 all whom it may concern: v Be it known that I, LOUIS JA'NssnNs, a subject of the King of Belgium, residingat Brussels, Belgium, haveinvented new and .useful Improvements in and Connected with the Synchronizing Apparatus.

This invention relates to a method of and arrangements for obtaining, first, the synchronous registering of a musical composition adapted to a cinematograph film during the production of this film, and afterward to permit an automatic reproduction of the composition thus registered in absolute agreement with the projection of the film representing the scene.

The object of the invention is to provide for each film an appropriate musical accompaniment which, at each stage of the projection, is. in perfect harmony with the scene projected. T

In the method of operationsin accordance with the invention a musical composition or improvisation appropriate to all the different phases of the cinematograph picture in question is performed. by a performer well acquainted with the picture upon a keyboard or bow instrument during the projeor tion of the film. This instrument is combined in' known manner with an apparatus which registers the musical performance by marks or perforations on a strip, which strip is drawn forward with a regular movement either by the .cinematograph motor which unwinds the film strip, or by a motor turning approximately synchronously with the cinematograph motor so that the said strip thus registered can be utilized in a', suitable instrument for the subsequent re-' production of the musical performance. Such registering and reproducing instruments with key-boards or bows are already known and used in practice and accordingly need not be described here.

ance and reproduction is a piano, that'the music record strip is registered by perforations and that the motor whichefi'ects the sametime to drive forward the film strip of the cinematograph, which may, however, be

driven also'by an independent motor.

, forward a uniform amount without any Specification of Letters Patent.

For the sake of clearness will be aS-- perforation of the music strip serves at the Patented chance of slipping because thefilm is always Dec. 26, 1916. a

perforated to engage the teeth of the drum.

Hence by using this .drum for recording the perforations, I can insure an exactrelationshlp between. the perforations and the film. Hence a music record strip is first-obtained which has. a series of perforations c0rresponding to similar perforations on a cinem'atograph film and the musical composition which is cbntained between each per oration exactly corresponds to the succession ofcinematograph pictures by which, the film has traveled forward'during this rotation.

By this means is obtained on this music:

strip a succession of, synchronism perforations such that the part of the musicalcom,

position registered between adjacent synbefore the projectinglens during the corresponding rotation of-the toothed drum in *fpliestion. By assuming that this portion of t e film strip is comprised between two perchronism perforations is in exact agreement forations which correspond exactly 'with two successive perforations marked on' the music strip, the registration of the latter can be obtained. This feature of the invention permits the utilization .in an automatic reproducing piano'of the musiq band thus registered, in order to automatically reproduce the piece ofmusiccorrespondin to a f givenfilm during the hproj ection of this film and in absolute agreement with the success.

sive scenes thereo 1 The synchronizing arrangement consists, of two movable members provided with) needles or-pointers, one of which members isdisplaced to a certain extent on the. passage of; a perforation on the music strip, while the-'other is displaced to a similar extent after a similar movement of the film,

each one of these members being provided with a variable-electric resistance one offloo which 1s in circuitwith the motor driving? the-music strip and the other of which is in circuit with the motor drivingthe film,

and the arrangement is such that the tensions of said resistances effective in the circuits of the motors is increased or diminished according as one member leads or lags relatively to the other. Thereby the current supply to the motors is modified so as to speed up the one which is lagging and to .110 damp the motion of the-one which is leadin order to play a musical record in absolute synchronism with the film it is suiticieot to arrange the film stripat the point of startingv in the cinematograph apparatus and to arrange the music strip at the point of starting in the reproducing piano, that is to say, in such a position that the first perforation of the musicstrip is in front of the tracker board. Then the cinematograph and the piano are simultaneously set in operation, taking care to regulate the speed of the two apparatus, so that at the moment of making each contact by the toothed drum of the cinematograph mechanism the synchronismperforation in the music strip corre sponding to this perforation passes in front of the tracker board.

The electrical mechanical apparatus here inafter described is used forautol'natically synchronizing the movements of the music strip over the tracker board, and the cinematograph film in front of the cinematograph apparatus. This apparatus is illustrated in the accompanying drawings, in which Figure 1 is a diagram showing the synchronizing apparatus. Fig. '2 is a diagrammatic form of construction of the apparatus as an example. Fig. 3 illu'strates'a detail of the synchronizing device. Fig. 4 illustrates diagrammatically by way of example,

a method of recording the perforations by an electro-mechanical device.

In the drawing, a. indicates the driving motor of the music strip in the reproducing piano and 6 indicates the driving-motor of the cinematograph film. it indicates a shaft, the extremity of which carries two diamct-. rically opposite arms y and .2 which are insulated from the shaft, for instance, as at I. *0 indicates a hollow shaft disposed around the shaft u. This second shaft r carries two sectors S arranged diametrically opposite to each other and wound with the coils of two resistances w and ac. A'variable portion of the resistance w can be inserted in or cut out of the circuit of the motor a by the displacement of the arm .2 (which forms a sliding connection witlr the coils of this resistance) when the shaft 10 turns relative to the hollow shaft 11. At the same time a portion of the resistance at, variable in the opposite sense to the portion of the resist- 'ance w is cut out of or inserted in the circuit of the motor I).

The circuit for the motor. (1, may be placed l on Fig. 1 so the positive lead 1 to the brush 2 through the rings 3 to the resistance 10, through the pointer .2 to the rings w through the b'rush't and the corresponding lead to a permanent resistance 5 and then through the motor a through the negative lead 6. A similar circuit for the motor I) is established from the positive lead 7 to the brush 8 to the ring 9', through the resistance {U to the pointer 37 through the ring 3 to the brush arness 10 to the permanent resistance 11, through the motor 0 to the negative .lead 12. It will be seen that the fixed or permanent resistances 5 need not be used. unless desired, but in practice it would not usually be necessary to wind themotors a and b for the full 110 volts'of the ordinary distribution circuit. Consequently the movement of the shaft to relative to the shaft 2: produces the acceleration of the motor a driving the music strip M. and at the same time produces the slowing down of the motor 1) driving the film or vice versa.

Referring to Figs. 2 and 3 the shaft it receives an intermittent rotary movement by means of a pawl Z acting upon the tooth of a ratchet wheel mounted on the said shaft. This pawl is actuated by an electro-magnet a, that is to say, at the-moment of the closing of an electric contact .2 at the end of each revolution of the special drum shaft'm in the cinematograph appai'atusby means of a pin. Y carried by one end of the drum.

The shaft o receives an intermittent movement hymeans ofa pawho acting upon a ratchet wheel 7) carried by this shaft. This pawl is actuated each time that one of the special. synchronism perforations in the music strip passes before the apertures in the tracker board. T of the reproducing piano. The movement of this second pawl is preferably produced by the pneumatic action resulting from the passage of the said perforations in front of the special aperture in the tracker board.

hen the perforation. registers with the aperture, air is admitted under piston 51') which thereupon is lifted by spring 51 so that the piston 52 closes thecontact Z of electromagnet n. It will be seen that magnets n and n are supplied with current from batteries L and L, respectively.

The ratchet wheels, the pawls, the special shaft establishing the electric contact, the music strip and the tracker board,'and also the electric and pneumatic connections. are not shown in the drawing since such member and arrangements are well known in current practice. g

The operation of the apparatus above described takes place as follows: At each passage of an imaginary reference mark'on the film in front of the objective'of the cinc-' matograph projector, that is to say, at each electrical contact madeby the special shaft X above mentioned, the shaft 11. will turn through a certain angle under the action of the pawl which makes the ratchet wheel m1 advance through a distance of one tooth. When passing over the tracker board the perforation in the music strip corresponding to this imaginary reference mark on the film will cause the second pawl to be moved and consequently will make the ratchet wheel 0 on the shaft 1) advance one tooth. If the time the agreement between the musicand passage of the imaginary. reference mark on the film and the corresponding perforation in the music strip takes place at the samethe cinematograph is correct. The two shafts u and 11 turn through the same angle at each passage andaccordingly the portions of the resistances w and a: in the circuits do not change, -that is to say, the speeds of the motors a and I) remain the same. If the imaginary reference mark on the film passes prior. to the corresponding perforation in the music strip, that is to say, if the film strip is in advance of the music .strip,

theshaft Q) will advance through a cer I tain angle relative to the shaft u and the arms y and awill be displaced on the resistances w and w respectively in the sense indicated by the arrows in Fig. 1." Consequently the portion of the resistance w in-' serted inthe circuit of the motor'a will decrease and the ortion of the'resistance :v

, in'the circuit 0 the motor I) will increase.

'In View of this, the movement of the motor a, that is to say, the movement of the music I strip, will'acceler'ate, while the movement of the motor I), that is, the movement of the film strip, will. slow down. In this manner the agr een git between the movement of the two strips tends constantly to reestablish'it self in an entirely automatic manner.

. The shaft it receives an intermittent rotation by means of a pawl E which acts on a. ratchet wheel m mounted on the shaftu,

Fig.3. This pawl is actuated by an electromagnet n and the circuit of ma each revolution of the shaft X in the cinematograph apparatus. which shaft carries tact. The shaft 1: receives 'anintermittentrotation by means of a pawl O, 'w-hich at each passage of a synchronous perforation Y of .the music strip M in frontof the opening S in the tracker board T of the pianoacts on a ratchet wheel p nounted on' this.

shaft by means of a vacuum controlled plunger which closes the contact Z in the circuit-v of magnet n, the circuit havingfa'source of current such as B. -'I he apparatus described work s as follows At each electrical contact made due to thefforward movement of ,the cinematograph film' the shaft a is turned through a certain angle by the pawl l' engaging the ratchet wheel m and thelatter being. thus 1 moved forward by one tooth," In passing '-the tracker board the perforation Y in the music strip M moves a second pawl o, and in this way turns by one tooth a ratchet wheel p provided on the shaft c. When the synchronism of the music and the pictures. is complete the two shafts u and 11 move to the same extent for corresponding movements of i of the atmosphere.

et' n is I closed by means of a contact Z at t e'end of synchronism in the the music strip and of the-filnuand the resistances w and w inserted .in the circuits do a the circuit of the motor I; will increase and hence the speed of the motor 6 will decrease, and hence in this manner both the motors will tend toward synchronism. It will be understood that the action of the synchronizing apparatus will be similarly effected toward synchronism when the shaft to lags behind the shaft o,that is the motor I) lags behind the IIlOtOlit. r

In practicethelength of'the music strip always-varies to a small extent according to the temperature and the hygrometricstate At the same time the size of the driving rollers of this strip is influenced by the same circumstances, and in addition this strip is liable-to slip on its rollers, resulting in the retardation of its movement. *The displacement of the imagin'ary reference marks of the film strip, which does not slip, is then, aspreviousl stated, always proportional to the speed 0 the motor which drives it in known manner, while the displacement of the synchronism perforations of the music strip is not proportional tothe speedof the motor which drives it, since the length of the band M between Qtw'o successive perforations. may become greater 'or smaller accordingto the hygrom'etric state of the atmosphere, and'besides the bandwmayslip while being driven. I In order to obtain automatically the synchronization of the music and cinematograph, it is not sufiicient (as! might have been supposed) to maintain a constant relation between the lengths 'of the film strip and the music strip which are driven forward .during the same period of time. In

'other words, it not su'fiicie'n to maintain here a rigorously constant relation between the speeds of movementof the mechanism drivingthe film and, the mechanism driving the music strip. The synchronization or bringing into agreement of the music and cinematograph by. the employment of reproducinginstrumentswi'th m'usic' strips is not then comparable with the synchronization of a phonograph and ci'nematograph, since, in.

the latter case,-it is suflicient to maintain .a

constant relation between the movements of cinematographic and The means of reallzation of two cases cannot, therethe phonographic mechanisms.

fore. becompared.

It is obvious that, in practice, for operation of the musical instrument of the c1nematograph apparatus either electrlc motors or any other suitable motors, hydraulic,

pneumatic, etc., maybe employed without departing from the scope of. the invention.

' Evidently the means for -regulating the hand, the needles A and B are located speed of these motors must be suited in each case to the motors.

In order to render'continually visible the .times of the passage'of the refereilce marks on the music strip and the corresponding marks on the film strip, it 'suilices to mount at the extremity ofthe shaft u and at the extremity of the shaft '0 two needles A and 13 after'themanuer of the hands of a watch, and to cause these needles to be displaced in front of a dial. If, for instance, the needle A is in advance of the needle B, the shaft t has received an angular displacement before the shaft 0, and vice versa. If, on the other above the other, the agreement between the music and cinematograph is absolute. The

means of realization of synchronism inthe two cases cannot therefore, be compared.

It has been assumed n the preceding description that the projection of the film wouldbe accompan ed by means of a single registering instrument or a slngle reproducing lnstrument, the instrument being a registering or reproducing piano.

It is quite evident that all that has been said is applicable to any instrument of which the sounds and musical tone variations can be registered on a strip and reproduced by employing this strip.

The initial projection ofia film could be accompanied simultaneously by means of several registering instruments with keyboards and with strings, for instance, piano, organ, harmomum, VlOllIl, Violoncello, double bass, harp,.-that is to say, by a complete orchestra, so that the synchronlsm perform tions can be marked at the same time on the s,

music strips registered by each instrument;

Such an orchestral musicalaccompanimenth of the film will then be able to'bereproduced' automatically in absolute agreement for each subsequent projection of this film by means of corresponding reproducing instruments.

Having now fully descrlbed and ascertained my said invention and-the manner in which it is to be performed, I declare that what I claim i s:-

1. An arrangement for maintaining synchronism between the music sheet of a tracker-board musical" instrument, and a cinematograph film comprising motors for driving the sheet. and the film, a synchronizing apparatus acting automatically to upon the passage of a corresponding point is in advance -a'nd to accelerate the motor ,tially as described.

maintain the continuous agreement ofv the passage of thereference marks of the music strip with the passage of the points of the film, which apparatus is characterized by a mechanism having two movable members, each provided with an indicator, means for giving one of said members a certain displacement at each passage of a reference mark on the music strip, and the other of said members an equal displacement in the same direction at each passage of a ,corresponding point of the film; this mechanism being'combined with.two electric resistances carried by one of the two members and two electric contacts carried by the other member and capable of being displaced over the resistance in one direction or the other according as the displacement pf one member is in advance of or behind, the displacement of the other; the circuits of the motors which actuate respectively, the music strip andfthe film strip, each including one of said sliding contacts and a portion of the above mentioned resistances whereby said portionvaries with the position of the contact on the resistance, substantially as described,

2. In apparatus of the class described in combination, .two members, means giving each memberthe same displacement at each passage of-a reference mark'on the music strip and forgiving theother member an equal displacement in the same direction on the film strip, said members comprising two concentric shafts mounted after the manner of the shafts of the hands of a watch, the outer shaft carrying two diametrically opposite sectors on each of which are wound the coils of aresistance, so arranged 'that a variable portion may be inserted in the circu1t of one of the two motors driving the strips,.while the inner shaft carries twp diametrical insulatedarms forming contacts sliding over the coils of the two resistances, which arms serve as connections between the resistances and the motors, in such a manner that if one shaft turns in advance of the other the displacement of the arms upon the coils produces simultaneous and inverse variations in the said resistances so as to. slowdown the motor driving the strip which driving the strip whidh is be hind, substan- V In testimony whereof I affiX my signature in presence of two witnesses.

LOUIS AN SSENS. Witnesses: i

BARTON MAEZ', CHAS. RoY NASMITH. 

